Hello. I'm using API functions to add a digital signature to a PDF document. While signing this document, I receive an error which looks like:

com.adobe.livecycle.signatures.client.types.exceptions.PDFOperationException: ALC-DSS-303-001 Could not sign Signature Field MyField (in the operation : sign)
Caused By: ALC-DSS-303-014 Subject name and the subject alt name missing. (in the operation : getSignerName)

My source code is a straight copy/paste from the SDK Help. I can successfully add an unsigned signature field using API call, but I can't sign it. I can also sign my document manually from Adobe Acrobat Professional using the same certificate.

I'm new in LiveCycle and digital signatures, so it might be some obvious reason that I just can't detect now.